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Dagger Board
A daggerboard is a retractable centreboard used by various sailing craft. While other types of centreboard may pivot to retract, a daggerboard slides in a casing. The shape of the daggerboard converts the forward motion into a windward lift, countering the leeward push of the sail. The theoretical centre of lateral resistance is on the trailing edge of the daggerboard. General A daggerboard is a removable vertical keel that is inserted through a "trunk" in the center of a vessel's hull, usually amidships. Daggerboards are usually found in small sailing craft such as day sailers, which are easily handled by a single person. Daggerboards are not usually ballasted but are locked in place by a clip or pin. Unlike a centreboard, which can be set at different angles to the hull of the boat, daggerboards are generally limited to a single perpendicular position relative to the hull. If a daggerboard is located off center, it is called a leeboard or a bilgeboard. The characteristic whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinghy Sailing
Dinghy sailing is the activity of sailing small boats by using five essential controls: * the sails * the foils (i.e. the daggerboard or centreboard and rudder and sometimes lifting foils as found on the Moth) * the trim (forward/rear angle of the boat in the water) * side-to-side balance of the dinghy by hiking or movement of the crew, particularly in windy weather ("move fast or swim") * the choice of route (in terms of existing and anticipated wind shifts, possible obstacles, other water traffic, currents, tides etc.) When racing, the above skills need to be refined and additional skills and techniques learned, such as the application of the "racing rules of sailing", boat handling skills when starting and when rounding marks, and knowledge of tactics and strategy. Racing tactics include positioning the boat at different angles. To improve speed when racing, sailors should position themselves at the windward direction (closest to the direction of the wind) in order to get " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanguard 15
The Vanguard 15 is an American sailing dinghy that was designed by Bob Ames as a one-design racer and first built in 1992.Sherwood, Richard M.: ''A Field Guide to Sailboats of North America, Second Edition'', pages 54-55. Houghton Mifflin Company, 1994. Production The design was built by Team Vanguard in the United States and later by LaserPerformance, but is no longer in production. Design The Vanguard 15 is a recreational sailboat, built predominantly of fiberglass. It has a fractional sloop rig with aluminum spars, a raked stem, a vertical transom, a transom-hung rudder controlled by a tiller and a retractable daggerboard. It displaces and is capable of planing upwind. The boat has a draft of with the daggerboard extended and with it retracted, allowing beaching or ground transportation on a trailer or car roof rack. For sailing the design is equipped with a boom vang and the mainsail and jib have windows for improved visibility. The halyards are external ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser (dinghy)
The Laser is a class of Single-handed sailing, single-handed, one-design dinghy sailing, sailing dinghies using a common hull design with three interchangeable rigs of different sail areas, appropriate to a given combination of wind strength and crew weight. Bruce Kirby (yachts), Bruce Kirby designed the Laser in 1970 with an emphasis on simplicity and performance. The Laser is a widely produced class of dinghies. As of 2018, there were more than 215,000 boats worldwide. It is an international class with sailors in 120 countries, and an Olympic class since 1996. Its wide acceptance is attributable to its robust construction, simple rig and ease of sailing that offer competitive racing due to tight class association controls which eliminate differences in hull, sails, and equipment. The International Laser Class Association (ILCA) defines the specifications and competition rules for the boat, which is officially referred to as the ILCA Dinghy, due to a trademark dispute. Other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mirror Dinghy
The Mirror is a type of popular sailing dinghy with more than 70,000 built. The Mirror was named after the ''Daily Mirror'', a UK newspaper with a largely working-class distribution. The Mirror was from the start promoted as an affordable boat, and as a design it has done a great deal to make dinghy sailing accessible to a wide audience. Although most popular in the UK, Mirrors are also sailed in other countries, notably Australia, Ireland, Sweden, Canada, the Netherlands, South Africa, New Zealand, the Philippines and the United States. Design The Mirror was designed by Jack Holt and TV do-it-yourself expert Barry Bucknell in 1962. It employed a novel construction method where sheets of marine plywood are held together with copper stitching and fibreglass tape. This is called tack and tape or stitch and glue construction. Buoyancy is provided by four independent integral chambers rather than by bags. It was originally designed to be built with simple tools and little experie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrodynamic
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion). Fluid dynamics has a wide range of applications, including calculating forces and moment (physics), moments on aircraft, determining the mass flow rate of petroleum through pipeline transport, pipelines, weather forecasting, predicting weather patterns, understanding nebulae in interstellar space and Nuclear weapon design, modelling fission weapon detonation. Fluid dynamics offers a systematic structure—which underlies these practical disciplines—that embraces empirical and semi-empirical laws derived from flow measurement and used to solve practical problems. The solution to a fluid dynamics problem typically involves the calculation of various properties of the fluid, such as flow velo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multihulls
A multihull is a boat or ship with more than one hull, whereas a vessel with a single hull is a monohull. The most common multihulls are catamarans (with two hulls), and trimarans (with three hulls). There are other types, with four or more hulls, but such examples are very rare and tend to be specialised for particular functions. Sailing multihulls Counter-intuitively, it is unhelpful to think of the design progression to be "1-2-3", namely monohull - catamaran - trimaran; rather, it is "1-3-2". A sailing trimaran is, in effect, a modified monohull with lightweight outrigger hulls (or "amas") for stability instead of a heavy deep keel; so it follows that a sailing trimaran will be lighter and faster than a sailing monohull. A sailing trimaran will have a centre hull that may comprise up to 90% of total hull volume, and 95% of total deadweight. A sailing trimaran at rest will have both amas out of the water and, when heeled, will only ever have one of the amas immersed. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monohulls
right A monohull is a type of boat having only one hull, unlike multihulled boats which can have two or more individual hulls connected to one another. Fundamental concept Among the earliest hulls were simple logs, but these were generally unstable and tended to roll over easily. Hollowing out the logs into a dugout canoe doesn't help much unless the hollow section penetrates below the log's center of buoyancy, then a load carried low in the cavity actually stabilizes the craft. Adding weight or ballast to the bottom of the hull or as low as possible within the hull adds stability. Naval architects place the center of gravity substantially below the center of buoyancy; in most cases this can only be achieved by adding weight or ballast. The use of stones and other weights as ballast can be traced back to the Romans, Phoenicians and Vikings. Modern ships carry tons of ballast in order to maintain their stability; even heavily laden cargo ships use ballast to optimize the dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schooner
A schooner () is a type of sailing vessel defined by its rig: fore-and-aft rigged on all of two or more masts and, in the case of a two-masted schooner, the foremast generally being shorter than the mainmast. A common variant, the topsail schooner also has a square topsail on the foremast, to which may be added a topgallant. Differing definitions leave uncertain whether the addition of a fore course would make such a vessel a brigantine. Many schooners are gaff-rigged, but other examples include Bermuda rig and the staysail schooner. The origins of schooner rigged vessels is obscure, but there is good evidence of them from the early 17th century in paintings by Dutch marine artists. The name "schooner" first appeared in eastern North America in the early 1700s. The name may be related to a Scots word meaning to skip over water, or to skip stones. The schooner rig was used in vessels with a wide range of purposes. On a fast hull, good ability to windward was useful for priv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes, which are Lake Superior, Superior, Lake Michigan, Michigan, Lake Huron, Huron, Lake Erie, Erie, and Lake Ontario, Ontario and are in general on or near the Canada–United States border. Hydrologically, lakes Lake Michigan–Huron, Michigan and Huron are a single body joined at the Straits of Mackinac. The Great Lakes Waterway enables modern travel and shipping by water among the lakes. The Great Lakes are the largest group of freshwater lakes on Earth by total area and are second-largest by total volume, containing 21% of the world's surface fresh water by volume. The total surface is , and the total volume (measured at the low water datum) is , slightly less than the volume of Lake Baikal (, 22–23% of the world's surface fresh water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Ontario
Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York. The Canada–United States border spans the centre of the lake. The Canadian cities of Toronto, Kingston, Mississauga, and Hamilton are located on the lake's northern and western shorelines, while the American city of Rochester is located on the south shore. In the Huron language, the name means "great lake". Its primary inlet is the Niagara River from Lake Erie. The last in the Great Lakes chain, Lake Ontario serves as the outlet to the Atlantic Ocean via the Saint Lawrence River, comprising the eastern end of the Saint Lawrence Seaway. The Moses-Saunders Power Dam regulates the water level of the lake. Geography Lake Ontario is the easternmost of the Great Lakes and the smallest in surface area (7,340 sq mi, 18,960 km2), although it exceeds Lake Eri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtling (sailing)
In dinghy sailing, a boat is said to be turtling or to turn turtle when the boat is fully inverted with the mast pointing down to the lake bottom, riverbed, or seabed. The name stems from the appearance of the upside-down boat, similar to the carapace (top shell) of a sea turtle. at Internet ArchiveHowever, "to turn turtle" means putting a turtle on its back by grabbing it by the flipper, and conversely is used to refer to a vessel that has turned upside down, or which has cast off its crew. A related nautical turtle metaphor is the term Turtleback Deck or "''deck, turtle'' nautical: A term applied to a weather deck that is rounded over from the shell of the ship so that it has a shape similar to the back of a turtle. Used on ships of the whaleback type and on the forward weather deck of torpedo boats." The term can be applied to any vessel; turning turtle is less frequent but more dangerous on ships than on smaller boats.In larger vessels a capsize almost inevitably leads to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
